ML022480150

Fort Calhoun, Licensing Amendment, Removing Reference to Specific Core Tilt Monitoring Computer Program

ML022480150
Person / Time
Site:	Fort Calhoun
Issue date:	10/29/2002
From:	Wang A NRC/NRR/DLPM/LPD4
To:	Ridenoure R Omaha Public Power District
Wang A, NRR/DLPM, 415-1445
References
Download: ML022480150 (10)

Text

October 29, 2002 Mr. R. T. Ridenoure Division Manager - Nuclear Operations Omaha Public Power District Fort Calhoun Station, FC-2-4 Adm.

P.O. Box 550 Fort Calhoun, NE 68023-0550

SUBJECT:

FORT CALHOUN STATION, UNIT NO. 1 - ISSUANCE OF AMENDMENT RE: REMOVING REFERENCE TO SPECIFIC CORE TILT MONITORING COMPUTER PROGRAM (TAC NO. MB5837)

Dear Mr. Ridenoure:

The Commission has issued the enclosed Amendment No. 211 to Facility Operating License No. DPR-40 for the Fort Calhoun Station, Unit No. 1. The amendment consists of changes to the Technical Specifications (TSs) in response to your application dated July 22, 2002.

The amendment removes from TS 2.10.4(4)a and b, Azimuthal Power Tilt (Tq), the reference to a specific computer program for monitoring core radial peaking factors when a core power tilt is present. Instead, the functional requirement is specified. This change clarifies the requirements for core tilt monitoring associated with a computer system upgrade and changes in computer programs. Also, a clarification is made in the Bases section for TS 2.10.4 regarding the application of TS 2.10.4(1)(b) when the plant computer incore detector alarms for monitoring core linear heat rate become inoperable.

A copy of the related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commission's next biweekly Federal Register notice.

Sincerely,

/RA/

Alan B. Wang, Project Manager, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-285

Enclosures:

1. Amendment No. 211 to DPR-40

2. Safety Evaluation cc w/encls: See next page

October 29, 2002 Mr. R. T. Ridenoure Division Manager - Nuclear Operations Omaha Public Power District Fort Calhoun Station, FC-2-4 Adm.

P.O. Box 550 Fort Calhoun, NE 68023-0550

SUBJECT:

FORT CALHOUN STATION, UNIT NO. 1 - ISSUANCE OF AMENDMENT RE: REMOVING REFERENCE TO SPECIFIC CORE TILT MONITORING COMPUTER PROGRAM (TAC NO. MB5837)

Dear Mr. Ridenoure:

The Commission has issued the enclosed Amendment No. 211 to Facility Operating License No. DPR-40 for the Fort Calhoun Station, Unit No. 1. The amendment consists of changes to the Technical Specifications (TSs) in response to your application dated July 22, 2002.

The amendment removes from TS 2.10.4(4)a and b, Azimuthal Power Tilt (Tq), the reference to a specific computer program for monitoring core radial peaking factors when a core power tilt is present. Instead, the functional requirement is specified. This change clarifies the requirements for core tilt monitoring associated with a computer system upgrade and changes in computer programs. Also, a clarification is made in the Bases section for TS 2.10.4 regarding the application of TS 2.10.4(1)(b) when the plant computer incore detector alarms for monitoring core linear heat rate become inoperable.

A copy of the related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commission's next biweekly Federal Register notice.

Sincerely,

/RA/

Alan B. Wang, Project Manager, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-285

Enclosures:

1. Amendment No. 211 to DPR-40

2. Safety Evaluation cc w/encls: See next page DISTRIBUTION:

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SDembek RidsOgcRp RidsNrrPMAWang WBeckner RidsNrrLAEPeyton CJohnson, RIV Package No.: ML023250255 TS Pages No.: ML023040247 ACCESSION NO.: ML022480150

• NLO w/Comments OFFICE PDIV-2/PM PDIV-2/PM PDIV-2/LA OGC

• SRXB/BC RORP PDIV-2/SC NAME AWang:rkb BPham EPeyton RWeisman JWermiel RDennig SDembek DATE 9/19/02 9/19/02 9/17/02 21 Oct 2002 10/2/02 10/4/02 10/28/02 OFFICIAL RECORD COPY

OMAHA PUBLIC POWER DISTRICT DOCKET NO. 50-285 FORT CALHOUN STATION, UNIT NO. 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 211 License No. DPR-40

1. The Nuclear Regulatory Commission (the Commission) has found that:

A. The application for amendment by the Omaha Public Power District (the licensee) dated July 22, 2002, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D. The issuance of this license amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.

2. Accordingly, Facility Operating License No. DPR-40 is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 3.B. of Facility Operating License No. DPR-40 is hereby amended to read as follows:

B. Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 211 , are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. The license amendment is effective as of its date of issuance and shall be implemented within 120 days of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Stephen Dembek, Chief, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: October 29, 2002

ATTACHMENT TO LICENSE AMENDMENT NO. 211 FACILITY OPERATING LICENSE NO. DPR-40 DOCKET NO. 50-285 Replace the following pages of Appendix A Technical Specifications with the attached revised pages. The revised pages are identified by amendment number and contain vertical lines indicating the areas of change.

REMOVE INSERT 2-57b 2-57b 2-57d 2-57d

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 211 TO FACILITY OPERATING LICENSE NO. DPR-40 OMAHA PUBLIC POWER DISTRICT FORT CALHOUN STATION, UNIT NO. 1 DOCKET NO. 50-285

1.0 INTRODUCTION

By application dated July 22, 2002, Omaha Public Power District (OPPD) requested changes to the Technical Specifications (TSs) (Appendix A to Facility Operating License No. DPR-40) for the Fort Calhoun Station, Unit No. 1. The proposed amendment would revise TS 2.10.4(4),

Azimuthal Power Tilt (Tq), to reference the functional requirement instead of a specific computer program for monitoring core radial peaking factors during a core power tilt.

2.0 REGULATORY REQUIREMENTS The Fort Calhoun Station design meets criteria similar to those now contained in 10 CFR Part 50, Appendix A, General Design Criteria for Nuclear Power Plants. The Fort Calhoun Station Updated Safety Analysis Report (USAR) Appendix G, Responses to 70 Criteria, describes how those criteria are met. The criteria that govern core power distribution monitoring are USAR, Appendix G, Criterion 6, Criterion 12, and Criterion 13. The change to the wording of TS 2.10.4(4) is being performed to clarify the requirements regarding core monitoring when a core power tilt is present.

3.0 TECHNICAL EVALUATION

The design basis states that either of the two core power distribution monitoring systems, the excore detector monitoring system or the incore detector monitoring system, provides adequate monitoring of the core power distribution and is capable of verifying that the linear heat rate (LHR) does not exceed its limit. The excore detector monitoring system performs this function by continuously monitoring the axial shape index with the operable quadrant symmetric excore neutron flux detectors. The incore detector monitoring system provides a direct measure of the radial peaking factors. The purpose of the CECOR program is to process fixed incore detector signals to calculate 3-D power distribution and peaking factors including FRT, "Total Integrated Radial Peaking Factor," FR, "Unrodded Integrated Radial Peaking Factor," and Tq, "Azimuthal Power Tilt," and peak LHR. The calculated value of FRT is defined as FRT = FR(1+Tq). The purpose of BASSS is to calculate allowable core power based on the axial power shape (ASI),

lead bank position and core peaking factors obtained from CECOR. On the current plant computer system, due to its limited capacity, these functions had to be combined in a single program called MINI-CECOR/BASSS.

TS 2.10.4(4) requires that FRT be monitored by the MINI-CECOR/BASSS program. This amendment request is being made in anticipation of a future change in the FRT monitoring program in conjunction with the upgrade to the plant computer which would remove the MINI-CECOR/BASSS program from the plant computer but still perform the monitoring of incore detectors using the CECOR methodology on which the MINI-CECOR/BASSS program is based. On the new plant computer system, with its greater capacity, the full versions of CECOR and BASSS can be installed as separate programs. For the purpose of monitoring the azimuthal tilt (TS 2.10.4(4)), only FRT must be monitored, and this can be calculated from CECOR directly.

BASSS used ABB/CE setpoints methodology to provide a larger departure from nucleate boiling (DNB) limiting condition for operation (LCO) for the ASI as opposed to the power operating envelope. However, since FCS has switched to the Framatome ANP setpoints methodology (referenced in the Core Operating Limits Report), the normal DNB LCO operating envelope and the BASSS DNB LCO operating envelope are identical. Therefore, BASSS is no longer needed, and OPPD plans not to install BASSS on the new plant computer system.

FCS has determined that rather than continuing to specify the specific computer programs (MINI-CECOR/BASSS) in TS 2.10.4, it is simpler and more efficient to specify the functional requirements and use the CECOR code which is an approved methodology. The CECOR/BASSS methodology is described in OPPD-NA-8301, Rev. 6, "Core Reload Analysis Method Overview," and OPPD-NA-8302, Rev. 4, "Neutronics Design Methods and Verification."

As set forth in a letter from the NRC to OPPD, dated December 16, 1994, the CECOR/BASSS methodology is contained in these codes. These codes are referenced in TS Section 5.9.5, "Core Operating Limits Report," and therefore, cannot be modified without NRC staff review and approval.

The proposed amendment would reference the functional requirement instead of a specific computer program for monitoring core radial peaking factors during a core power tilt. This change would clarify the requirements for core tilt monitoring associated with a computer system upgrade and changes in computer programs. Until the plant computer is upgraded there will be no change in the method of computing FRT because the MINI-CECOR/BASSS program will continue to be used as it is now. When the plant computer is replaced, the FRT will be maintained by the CECOR program which the MINI-CECOR/BASSS program was based on.

The proposed amendment does not change the design basis or methodology for core power distribution monitoring.

OPPDs proposed amendment only changes the wording of the core power distribution monitoring specifications, and therefore, will not result in any changes to the monitoring requirements or analysis values used for the design basis. The surveillance requirements for verifying that FRT and Tq are within their limits, provide assurance that the actual values of FRT and Tq do not exceed the assumed values. The method for the calculation of the FRT values is unchanged and the FRT TS limits assure that the TS limitation on LHR is met in the event of a loss-of-coolant accident, and therefore, the peak temperature of the fuel cladding will not exceed 2200 °F. In addition, the MINI-CECOR/BASSS program will be left running on the old

computer system. During this time, results from the CECOR program running on the plant computer will be checked against MINI-CECOR/BASSS and also against an off-line version of CECOR. This will confirm the accuracy of the CECOR program on the new computer system.

For these reasons, the NRC staff finds that the proposed TS changes are acceptable.

Bases Section 2.10.4, "Power Distribution Limits," has been revised to reflect the proposed TS changes. The staff has reviewed these Bases changes and has no objection to them.

4.0 STATE CONSULTATION

In accordance with the Commissions regulations, the Nebraska State official was notified of the proposed issuance of the amendment. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding (67 FR 56326). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.

6.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: B. Pham Date: October 29, 2002

Ft. Calhoun Station, Unit 1 cc:

Winston & Strawn Mr. Richard P. Clemens ATTN: James R. Curtiss, Esq. Division Manager - Nuclear Assessments 1400 L Street, N.W. Omaha Public Power District Washington, DC 20005-3502 Fort Calhoun Station P.O. Box 550 Chairman Fort Calhoun, Nebraska 68023-0550 Washington County Board of Supervisors Mr. Daniel K. McGhee P.O. Box 466 Bureau of Radiological Health Blair, NE 68008 Iowa Department of Public Health 401 SW 7th Street Mr. John Kramer, Resident Inspector Suite D U.S. Nuclear Regulatory Commission Des Moines, IA 50309 P.O. Box 310 Fort Calhoun, NE 68023 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011 Ms. Sue Semerera, Section Administrator Nebraska Health and Human Services Systems Division of Public Health Assurance Consumer Services Section 301 Cententiall Mall, South P.O. Box 95007 Lincoln, Nebraska 68509-5007 Mr. David J. Bannister Manager - Fort Calhoun Station Omaha Public Power District Fort Calhoun Station FC-1-1 Plant P.O. Box 550 Fort Calhoun, NE 68023-0550 Mr. John B. Herman Manager - Nuclear Licensing Omaha Public Power District Fort Calhoun Station FC-2-4 Adm.

P.O. Box 550 Fort Calhoun, NE 68023-0550